The invention relates to an improved hose bundle, and in particular to an improvement in hose bundles such as those having fluid or electric control lines which extend from control equipment to a petroleum well at a location which is remote from the control equipment.
In the field of petroleum production, numerous hoses and other conduits, often several hundred feet in length, are used for controlling valves and other equipment associated with a petroleum well. For example, blow-out prevention devices located underwater at a well require a plurality of hoses or conduits extending from the equipment located above the water for separately operating a plurality of hydraulic, pneumatic and/or electrically operated valves. As can be appreciated, it is important that such hoses or conduits be secured to prevent tangling, kinking or damage and are preferably secured such that they are capable of being handled with pulleys, reels and the like. For this reason, the hoses or conduits leading to a particular area of the well, e.g. a blow out prevention device, are frequently secured together to form a unitized bundle. The term "conduit" as used herein is intended to include hoses for fluid as well as electrical cables or wires, wire ropes or other elongate members.
One technique for forming a unitized bundle of conduits is taught in U.S. Pat. No. 4,309,869 to Boyce. As taught therein, the hoses are wrapped about a central core, in multiple layers, using the apparatus disclosed in the patent. After the bundle is collected on a collecting reel, a covering or sheath is extruded about the bundle to provide an overall flexible protective coating for the bundle. In the past, when the number of hoses needed in any particular multi-conduit line was less than the number necessary to form a substantially cylindrical layer about the central core, fillers such as fiber rope have been used for filling up the spaces.
Spaces or voids within the bundle are undesirable for several reasons. One reason is that voids permit the hoses to move within the extruded protective layer during manufacture and handling and thereby increase the risk of damage to the hoses. Although the industry has accepted the use of fiber fillers for many years, their use has drawbacks. For example, although fiber rope initally creates a relatively tight bundle, the fiber tends to compress and become displaced as the bundle is handled in service. Moreover, the fiber filler is more susceptible to general deterioration and rotting than the other components of the bundle. In general, such bundles are not sealed at their ends so that, when used in undersea wells, sea water can enter the bundle and hasten deterioration of fillers. Compression and/or deterioration of the filler can lead to movement of the conduits within the outer sleeve and a return to the problems noted above. In addition, because of the compressibility of the filler material, its use often results in a bundle of irregular cross-section.
To decrease the compression and deterioration problems, scrap plastic tubing has sometimes been used instead of fiber rope fillers. Although the use of such plastic tubing is a partial solution to the problem, the addition of tubing filler has required that the cabling machine be utilized to incorporate the filler in the bundle. This frequently involves an additional pass of the cabling machine over the core which significantly increases the time and labor costs of manufacturing the bundle.
Another problem with the use of fillers is that their incorporation results in a bundle which does not have uniform impact resistance or compressibility. In other words, the fillers have different impact and stress resistance than the adjacent hoses and hence create local areas which are more susceptible to impact or compression damage. Thus, the fillers result in overall bundle durability less than would be obtained in the absence of such fillers. Typically circular clamps are used to secure the bundle to ropes for lowering it to the ocean floor in an undersea well, and to maintain the bundle in position to prevent stress on the connections between the bundle hoses and associated control devices. These clamps represent a constant external load on the bundle in service. When fillers are used, the load is imbalanced relative to the bundle hoses which, as can be appreciated, is detrimental to the integrity and consequent durability of the bundle, effectively decreasing its serviceable life. In general, the more filler incorporated in a bundle, the less durable it will be in service.
U.S. Pat. No. 4,262,703 to Moore et al. teaches a technique for minimizing damage from impacts to a bundle of control lines. The Moore technique includes incorporating wire ropes of slightly larger diameter than the hoses to provide impact-resistant, load-bearing members to prevent planar forces from directly contacting the protected control lines. Although incorporating wire ropes may improve impact resistance of a bundle, the ropes usually lead to a bundle having an irregular or non-circular cross-section, which again would not react uniformly to external, non-impact type loading, e.g. by securing clamps.
In addition to having a more durable bundle, it would also be advantageous to have a unitized hose bundle which has a generally circular, relatively uniform overall cross-section for ease in utilizing pulleys, for packaging on reels, as well as for maximizing durability.